Method and apparatus for making felted materials



prl 10, i945. G T PEARCE 2,373,500

METHOD AND APPARATUS FOR MAKING FELTED MATERIALS Filed Jan. 1, 1945lNVENTOR N 41E 7.' fof/1HE.

BY ATTORN EY Patented Apr. 10, 1945 METHOD AND APPARATUS FOR MAKINGFELTED MATERIALS Gale T. Pearce, Somerville, N. J., assigner to VJohns-Manville Corporation, New York, N. Y., a corporation of New YorkApplication January 1, 1943, Serial No. 471,072

12 Claims.

This invention rel-ates to felted sheet materials such as fibrous blocksor batts and more particularly to those made from mineral wool fibers.It will be understood that the term mineral wool is employed herein in ageneric sense to denote fibers formed from rock, slag, glass, and otherlike raw materials and mixtures thereof.

Heretofore in the manufacture of felted slabs and sheets of mineral woolfibers a suitable raw mineral wool forming material is melted andthemolten material shredded by means of a high pressure steam jet or thelike into a multiplicity of fibers. The fibers are carried, whilesuspended ln an air stream, into a collecting chamber where they settlefrom the air stream onto the bottom of the chamber, the latter usuallycomprising aA continuously moving conveyor. Suitably a binder is addedadjacent the place of formation of the fibers, the ne particles ofbinder being carried into the blow chamber with the fibers and settlingwith them to become intermingled therewith throughout the thickness ofthe felt. Thereafter the felt is subjected to treatment to set tinebinder, preferably while the felt is under compression, whereby aresilient, compressible product is formed.

Although the product, formed as briefly described above, has been widelyused, it is found that particularly for some purposes, it does not havecertain desired properties. The fibers falling onto the conveyor or ontothe previously deposited bers assume positions generally parallel to theconveyor, this being accentuated by the forward movement of theconveyor. As a result, the fibers lie predominantly in a series ofplanes generally parallel to the faces of the' felted product impartinga high degree of compressibility thereto. Also, due to the resiliency ofthe felted material and the diiculty of achieving uniform distributionof the fibers throughout the Width of the felt, variations in densityand thickness of the felt occur. It has been found, for example, thatthe thickness cannot, be controlled successfully within a plus or minus15 percent of that desired.

The principal object of the invention is the provision of a method andapparatus which will produce a felt of uniform thickness and of greaterresistance to compression and delamination.

Another object of the invention is the provision of a method andapparatus of the above referred to type which will permit anypredetermined thickness of the material to be obtained within closelimits.

A further object of the invention is the provision of a method and meansfor reorienting the fiber arrangement of the known type of mineral woolproducts, and more specifically to producea material of this typeincluding facing sheets yapplied over both surfaces of the iibrous body.

further objects and advantages thereof will become apparent whenreference is made to the more detailed description thereof which is tofollow and to the accompanying drawing in which:

Fig. 1 is a diagrammatic lside elevational view of an apparatus inaccordance with the invention and to be employed for performing themethod;

Fig. 2 is a diagrammatic top plan view of the apparatus of Fig. 1;

Fig. 3 is a detail view on an enlarged scale of a portion of theapparatus of Fig. 1;

Figs. 4a, 4b, and 4c are sectional views on an enlarged scale taken onthe lines 4af-4a, 4b-4b and 4c-4c respectively, of Fig. 2.

Referring now to the drawing. opposed conveyors I0 and I2 supported ondriven rolls I8 and I8 are shown for supporting and causing forwardmovement of a felt I4. The'felt, as previously referred to, is suitablyone in which the fibers lie predominantly in planes parallel to thefaces of the felt, for example, a mineral wool felt made bydisintegrating a stream of molten material into fibers and collectingthe fibers on a conveyor forming the iioor of a blow chamber. Preferablythe felt includes a suitable binder and at the stage illustrated in Fig.1, the felt or sheet I4 has been compressed, and the binder set. In thepreferred embodiment, felted sheet I4 is supported directly andcontinuously from its place of formation to conveyors I0 and l2 althoughpreviously formed and stored felts may be used if desired.

Adjacent the forward ends of conveyors I0 and I2 are a plurality ofsharp edged disks or saws 20 keyed or otherwise secured to a shaft 22for rotation therewith, the disks constituting slitting or cuttingmeans. Preferably the mounting of the disks is such that the distancesbetween them may be adjusted when desired.

Forwardly of the slitting disks are a plurality of troughs 24 each madeup of thin metal or the like. One side of the rearward end of eachtrough is closely adjacent and in alignment with a disk. Troughs 24 aretwisted through an angle of 90 degrees as illustrated more particularlyin Fig. 3 and their forward ends are fanned out as shown in Fig. 2 todefine spaces between the ends of the several troughs. The troughscomprise an L shaped portion 26 and an additional flange 21 defining anopposite side over the greater length of the trough. Flange21 ispreferably of less Width than the sides of the L shaped portion andtapers to zero width adjacent the ends of the trough as illustrated inFigs. 3 and 4c.

Forwardly of troughs 24 are opposed upper and lower conveyor belts 28and 30, respectively, travelling in the direction indicatedby the arrowson driven rolls 29 and 3| respectively. Upper conveyor belt 28 issuitably mounted for adjustment relatively to conveyor 30. Associatedwith conveyors 28 and 30 are compression belts 32 carried by rolls 34and 36, the latter rotating on vertical axes. Belts 32 are suitablyformed of thin steel strips or the like, the strips being of a width tobe accommodated between the adjacent reaches of belts 28 and 30 in anyposition of vertical adjustment of belt 28. The inner reaches of belts32 lie between the adjacent reaches of belts 28 and 38 and converge asillustrated to provide edge compressing means. The convergence of thebelts may be Obtained as shown by employing rolls or pulleys 36 ofgreater diameter than rolls 34 or alternatively the rolls may be of thesame or similar diameter and their axes lie in converging planes.

In a line with belts 28 and 30 are another pair of opposed belts 38 and40 supported on rollers 39 and 4I respectively and travelling in thesame direction as those previously described as indicated by the arrows.Beltv40 is suitably mounted for adjustment relative to the lower belt 38similarly as belt 28. Above belt 40 there is provided a supply 42 ofsheet facing material`44, the sup-` ply comprising a spool of thematerial mounted on a spindle 46. A similar spool or other supply offlat semi-rigid metal or composition sheets of facing material 48 ismounted in any suitable location below the conveyors. Coating applyingdevices such as spray heads 4l and 49 connected to any suitable sourceof adhesive supply, are located in position to coat the facing materialas it is drawn from the supplies. Forwardly of conveyors 38 and 40 areedge slitting disks 50. keyed or otherwise secured to a shaft 52 forrotation therewith. If desired. shaft 52 may carry additional slittingdisks to divide the sheet longitudinally into strips or batts of anydesired width.

'Ihe several conveyors are driven by any suitable means (not shown) andat the same speeds. One main driver may be employed or if desiredseparate drivers for each set of conveyors may be used. The shafts 22and 52 supporting slitting disks 20 and 50 are rotated at high speed bysuitable driving means which may constitute the same means employed todrive the several conveyors.

In the operation of the apparatus described above and in carrying outthe preferred method of the invention a sheet or blanket of feltedfibrous material, suitably a mineral wool blanket, formed as previouslydescribed and with the fibers lying predominantly in planes parallel tothe face of the felt, is conveyed directly from the felt formingoperations to conveyor i by which it is carried into the bight betweenconveyor i0 and conveyor I2 and forced forwardly against the slittingdisks 20, which divide it into a plurality of strips I54.

The width of the strips is determined by the spacing of the slitterdisks 28 and is made substantially equal to the desired thickness of theIfinished product. The strips subdivided from the sheet I4 by theslitter disks enter the troughs 24 and are twisted through an angle of90 degrees as they travel through the troughs to cause their slitsurfaces to assume the positions of the top and bottom faces of thestrips as disclosed particularly in Figs, 4a, 4b, and 4c. Thus it Willbe noted from an examination of these figures that the side A, whichimmediately after the slitting operation constituted the upper face ofthe strip, is gradually rotated in the trough until it becomes a sideedge of the strip (see Fig. 4c). It will be understood that although aparticular means for rotating the strips through the 90 degree angle hasbeen shown other equivalent means may be employed for this purpose.

As the strips leave the troughs, with their slit faces forming theirupper and lower surfaces, they are picked up -by conveyors 28 and 30.which are adjusted a suflicient distance apart to confine the stripstherebetween and provide a frictional Contact against both surfaces. Asthe strips are moved forwardly by these conveyor belts they aresubjected to lateral movement by pressure belts 32 which converge asillustrated in Fig. 2 to reassemble the strips in edgewise contiguousrelationship and to preferably place them under at least some degree oflateral compression. The sheet or mat composed of the combined stripsthen passes into the bight between belts 38 and 40 at which pointsurfacing sheets 44 and 48 are applied. The surfacing sheets maycomprise any suitable material for this purpose, for example, kraftpaper, a felt of the type of sheathing felt, metal sheets, a woven clothor the like and may carry any suitable impregnant or coating material ormay be of a type to receive decorative coatings. The surfacing materialmay be supplied in continuous lengths from the supply rolls, the upperroll being sho'wn at 42, or may be fed in successive sheets from anysuitable supply means. Surfacing sheet 44 for the upper face of thefelted mat is supplied with an adhesive coating as by the spray head 41and is then passed between the upper conveyor 40 and the mat whereby itis pressed against and adbesively secured to the felted mat. Surfacingsheet 48 is similarly supplied with an adhesive coating and applied tothe lower face of the felted mat. During the travel of the materialbetween the conveyors the adhesive is set or substantially so. Anysuitable type-of adhesive may be employed. .The sheet or mat then passesto the slitters 50 where its edges are trimmed and it is divided intostrips if desired. The material may then pass to cut-off devices todivide it into units of the required length and to any further finishingand handling operations.

By the instant invention the ber arrangement of the felted material isreoriented to critically modify certain characteristics of the feltedsheet. The original material was of a laminar structure, as previouslypointed out, with the laminations lying substantially parallel to thefaces of the felt. Consequently, the material was subject tocomparatively easy delamination. Also, due to the arrangement of thefibers predominantly parallel to the faces of the sheet, the materialwas highly compressible. In the product of the instant invention, atleast a high percentage of the fibers lie in planes extendingsubstantially vertically to the faces of the felted sheet whereby boththe compression resistance and resistance to delamination are greatlyincreased. Inasmuch as the thickness of the material is determined bythe setting of slitters 20, this dimension may be fixed as desired andwill be uniform throughout. Thus variations due to uneven distributionof the fibers in the blow chamber and the like do not seriously affectthe dimensions or other essential characteristics of the finishedproduct. The surfacing sheets provide smooth impact resistant faces forthe product and may carry suitable decorative finishes.

Having thus described my invention in rather full detail, it will beunderstood that these details need not be strictly adhered to but thatthe various changes and modifications will suggest themselves to oneskilled in the art, all falling within 2,878,500 the scope of theinvention as defined by the subjoined claims.

What I claim is: I

1. A method of making a product from a sheet of felted fibers in whichthe fibers lie predominantly in planes parallel to the faces of thesheet. said method comprising dividing the sheet by slits extendingthrough the sheet at substantially right angles to the major faces ofthe sheet into a plurality of strips of predetermined Width, rotatingsaid strips through an angle of 90 and recombining said strips into asubstantially unitary body.

2. A method of making a uniform thickness product from a sheet of feltedfibers in which the fibers lie predominantly in planes parallel to thefaces of the sheet, said method comprising dividing the sheet into aplurality of strips of predetermined substantially equal width by slitsextending through the sheet and substantially at right angles to themajor faces thereof, rotatingr said strips until their slit edges lie inthe same planes and assembling said strips in contiguous relationshipwith their slit edges lying in said planes.

3. A method of making a product from a sheet offelted mineral wool bersin which the bers lie predominantly in planes parallel tothe faces ofthe sheet, said method comprising dividing the sheet into a plurality ofstrips of predetermined width by slits extending through the sheet atsubstantially right angles to the major faces thereof, rotating saidstrips through an angle of 90, assembling said strips into continguousrelationship and adheslvely applying a facing sheet to a surface of saidassembled strips.

4. A method of making a substantially uniform thickness product from asheet of felted mineral wool fibers in which the fibers liepredominantly in planes parallel to the faces of the sheet, said methodcomprising dividing the sheet lnto a plurality of strips ofpredetermined equal width by slits extending through the sheet atsubstantially right angles to the major faces thereof, rotating saidstrips until the slit edges thereof lie in the same planes, assemblingsaid strips into contiguous relationship while maintaining said faces insaid planes and adheslvely securing facing sheets to said assembledstrips.

5. AThe continuous method of making a uniform thickness product from asheet of felted mineral wool fibers in which the fibers liepredominantly in planes parallel to the faces of the sheet, said methodcomprising dividing the sheet continuously with its formation into aplurality of strips by slits extending through the sheet atsubstantially right angles to the major faces thereof, moving saidstrips forwardly, twisting said strips through an angle of substantially90 during their forward travel to rotate their slit edges into commonplanes, assembling said strips in edgewise contiguous relationship andadhesively securing facing sheets to said assembled strips.

6. An apparatus for reorienting the fibers in a felted fibrous sheetcomprising a plurality of equally spaced slitters in alignment with asheet delivering means, means to rotate the strips issuing from theslitters through an angle of 90 and to place said strips in spacedrelationship with their slit edges lying in the same planes. and meansforassembling said strips into contiguous relationship while maintainingtheir slit edges in said planes.

7. An apparatus for reorienting the fibers in a felted fibrous sheetcomprising a plurality of equally spaced slitters in alignment with asheet delivering means, means to rotate the strips issuing from theslittersthrough an angle of and to place said strips in spacedrelationship with their slit edges lying in the same planes, means forassembling said strips into contiguous relationship while maintainingthe slit edgesof said strips in said planes, and means for applyingsheet material to opposite faces of said combined strips.

8. An apparatus for reorienting the fibrous structure in a feltedfibrous sheet comprising a plurality of slitters equally spaced acrossthe width of said sheet. means to rotate the strips of said sheetissuing from the slitters through an angle of 90 and to place saidstrips in spaced relationship with their slit surfaces in the sameplanes, opposed conveyors for contacting said slit surfaces and formoving the strips forwardly, and pressure means for forcing the stripslatterally into contiguous relationship as they are moved forwardly bysaid conveyors.

9. An apparatus for reorienting the fibrous structure in a feltedfibrous sheet comprising a plurality of slitters equally spaced acrossthe width of said sheet, means to rotate the strips issuing from theslitters through an angle of 90" and to place said strips in spacedrelationship with their slit faces inthe same planes, ODPOSed conveyorscontacting said faces of said strips for moving the same forwardly,pressure means for forcing the strips into contiguous relationship asthey are moved forwardly by said conveyors, and means for adheslvelysecuring sheet material to opposite faces of said contiguous strips.

1o. An apparatus for modifying a felted fibrous sheet, the apparatuscomprising a plurality of slitters equally spaced across the width ofsaid sheet, means to rotate the strips issuing from the slitters and toplace said strips in spaced relationship with their slit faces in thesame planes, opposed conveyors contacting said faces of said strips formoving the strips forwardly, opposed belts extending between saidopposed conveyors for moving said strips laterally into contiguousrelationship, and means for securing a surfacing sheet to a face of saidcontiguous strips.

11. A method of making a uniform thicknessI sheet product from a sheetof felted fibers in which the fibers lie predominantly in planeslparallel to the faces of the sheet, said method comprising dividing thesheet into a plurality of strips of predetermined, substantially equalwidth by slits extending through the sheet. rotating said strips untiltheir slit edges lie ln the same planes, and assembling said strips incontiguous relationship with their slit edges lying in said planes toform opposite surfaces of the assembly.

l2. A method of making a uniform thickness sheet product from a sheet offelted bers in which the fibers lie predominantly in planes parallel tothe faces of the sheet. said method comprising dividing the sheet into aplurality of strips of predetermined, substantially equal width by slitsextending through the sheet, rotating said strips until their slit edgeslie in the same planes. assembling said strips in contiguousrelationship with the slit edges lying in said planes to form theopposite surfaces of the assembly. and adheslvely applying facing sheetsto said surfaces.

GALE T. PEARCE.

